The present invention refers to a sealing device for an interspace between two surfaces.
The invention is primarily intended to be used for the sealing of the interspace between a shaft and its through hole in a bearing housing, but other applications are of course possible.
In order to obtain a good sealing effect it is essentially that the sealing body engages the surfaces defining the interspace to be sealed off. If the surfaces are movable relative to each other the portion of the sealing body which engages the movable surface should consist of material which can be supplied with lubricant and which will cause no wear on the movable surface in order to avoid friction losses and wear which will reduce the sealing function. The seal should furthermore be resistant to mechanical and chemical influence and be as inexpensive as possible. For those portions of the sealing body which engage a movable surface a material which is highly flexible and/or self-lubricating or able to absorb large quantities of lubricant is generally used. Such materials, however, often have low strength and may, therefore, not be used for the sealing body in cases where interspaces of comparatively large height shall be sealed off and where the seal may be subjected to high stresses. In view of this, seals have been designed, which incorporate portions of different material, e.g. a combination of metal and rubber. Such seals are rather complex and, therefore, expensive to manufacture, which is further stressed by the fact that their rigidity entails that interspaces of different size and shape will require different seals. This has a negative influence on the possibility of producing seals in long series, which could reduce the cost.